The following prior art publications are considered to be relevant for an understanding of the prior art:
U.S. Pat. No. 7,524,317 to Gruzdev et al.
U.S. Pat. No. 8,788,045B2 to Gross
U.S. Pat. No. 6,735,474 to Loeb
U.S. Pat. No. 8,406,886 to Gaunt et al.
U.S. Pat. No. 8,577,458 to Libbus et al.
U.S. Pat. No. 6,148,232 to Avrahami
Transcutaneous electrical nerve stimulation (TENS) is a non-invasive treatment which involves the placement of surface electrodes on the surface of the skin, and the use of an electric current to stimulate nerves for therapeutic purposes. Various medical devices are known that provide transcutaneous electrical stimulation using surface electrodes, for use in many kinds of treatments, such us pain relief, pain treatment, disease treatment, chronic disease treatment and rehabilitation. Penetration of an electric current through a tissue barrier, such as the skin, is limited by the resistance or impedance of the tissue, so that a tolerable electric current will typically only reach superficial nerves. Increasing the current in order to stimulate deeper nerves can result in pain, burning and irritation.
Medical devices are also known that perform percutaneous electrical nerve stimulation (PENS), which is a minimal invasive treatment, in which an ultra-fine acupuncture needle is introduced into a tissue and which penetrates into soft tissues or muscles to electrically stimulate nerve fibers. The acupuncture needle has to be inserted at the precise treatment location and sometimes causes pain and bleeding.
Other medical devices are known that puncture the stratum corneum layer of the skin in order to increase the permeability of the skin to therapeutic compounds. These devices utilize such energy sources as RF currents, ultrasonic waves, laser beams and resistive heating energy technology. These are mainly used for esthetic treatments and also as first stage for allowing transdermal delivery of large molecules such as pharmaceuticals. Such a device is disclosed, for example, in U.S. Pat. No. 7,524,317 to Gruzdev et al.
U.S. Pat. No. 8,788,045B2 to Gross describes a device which includes electrodes that are placed within 1 mm of the tibial nerve of a subject and are driven to treat polyneuropathy by driving a current into the tibial nerve. Polyneuropathy is damage or disease affecting peripheral nerves (peripheral neuropathy) in roughly the same areas on both sides of the body, featuring weakness, numbness, pins-and-needles, and burning pain.
U.S. Pat. No. 6,735,474 to Loeb describes a system for treatment of incontinence and/or pelvic pain that includes injection or laparoscopic implantation of one or more battery or radio frequency-powered micro-stimulators beneath the skin of the perineum and/or adjacent the tibial nerve. The system and method tends to reduce the incidence of unintentional episodes of bladder emptying by stimulating nerve pathways that diminish involuntary bladder contractions. The incidence of fecal incontinence is similarly reduced or eliminated.
Also known is a system for treatment of chronic pain by delivering high-frequency stimulation to sensory nerves in the peripheral nervous system to block chronic pain. An electrode is placed around a peripheral nerve and powered by a pacemaker-size generator.
A minimally-invasive system is also known that delivers percutaneous tibial nerve stimulation for treatment of overactive bladder (OAB) and the associated symptoms of urinary urgency, urinary frequency, and urge incontinence. The system is used in percutaneous stimulation to deliver to the tibial nerve electrical pulses that travel to the sacral nerve plexus, a control center for bladder function.
A system for the treatment of chronic pain of peripheral nerve origin has been disclosed in which electrical signals are transmitted transdermally through an electrode, down a lead to a target nerve. While this device might target electrical stimulation to the targeted nerve, the passage of the stimulation energy is reduced dramatically by the stratum-corneum.
U.S. Pat. No. 8,406,886 describes an implant, system and method for treating a disorder of the nervous system in a subject. The method involves using passive electrical conductors which route electrical current to electrically stimulate a target body tissue to either activate or block neural impulses depending upon the frequency and the disorder to be treated. Electrically-excitable bodily tissues such as nerves and muscles may be activated by an electrical energy applied between electrodes applied externally to the skin. Electrical energy, e.g. current, flows through the skin between a cathode electrode and an anode electrode, eliciting action potentials in the nerves and muscles underlying the electrodes. This method has been used for many years in different types of stimulators, including transcutaneous electrical nerve stimulators (TENS) which relieve pain, therapeutic electrical stimulators which activate muscles for exercise purposes, functional electrical stimulators which activate muscles for tasks of daily life and stimulators that promote regeneration of damaged bones.
U.S. Pat. No. 8,577,458 describes an implantable device for providing electrical stimulation of cervical vagus nerves for treatment of chronic cardiac dysfunction with leadless heart rate monitoring. A stimulation therapy lead includes helical electrodes configured to conform to an outer diameter of a cervical vagus nerve sheath, and a set of connector pins electrically connected to the helical electrodes. A neuro-stimulator includes an electrical receptacle into which the connector pins are securely and electrically coupled. The neuro-stimulator also includes a pulse generator configured to therapeutically stimulate the vagus nerve through the helical electrodes in alternating cycles of stimuli application and stimuli inhibition that are tuned to both efferently activate the heart's intrinsic nervous system and afferently activate the patient's central reflexes by triggering bi-directional action potentials.
U.S. Pat. No. 6,148,232 to Avrahami describes a device for ablating the stratum corneum epidermidis.